Validation of the ipsilateral nipple as the needle directional guide during right internal jugular vein catheterization: A prospective observational study.

Our study shows that when the needle is inserted at the apex of the anatomical triangle directed towards the ipsilateral nipple, it crosses the IJV at 16°. Since the common carotid artery is usually medial to the IJV, directing the needle towards the ipsilateral nipple seems to be a safe way to avoid the common carotid artery and successfully puncture the IJV.